3 Big Milestones in the Development of Twitter 'Language' The first @reply, hashtag and retweet happened less than a decade ago, but in the world of social media, they're historic.

Kudos to Quartz, which is celebrating some social media pioneers. The site recently published a post that reveals the very first hashtag, @reply and retweet—the holy trinity of Twitter engagement.

The first @reply comes to us from Robert Anderson, who, according to his bio, is now a creative director at payments-app company Square.

@ buzz - you broke your thumb and youre still twittering? that's some serious devotion

— Robert S Andersen (@rsa) November 3, 2006

Even since, the @ has meant that you're talking to someone or, at the very least, mentioning them in a way that you want them to know you're talking about them.

The @reply became an official Twitter feature in 2007, about a year after the site launched.

Chris Messina brought us the first hashtag:

how do you feel about using # (pound) for groups. As in #barcamp [msg]?

— Chris Messina™ (@chrismessina) August 23, 2007

Although that tweet was published in August 2007, the New York Times didn't declare hashtags a trend until much later, in this 2011 article.

It's noteworthy that the first hashtag was aimed at creating "groups," where now they're just used to annoy people who don't know what a hashtag is or label jokes about the latest news item.

And the first retweet? You can thank Eric Rice for that.

ReTweet: jmalthus @spin Yes! Web2.0 is about social media, and guess what people like to be social about? Themselves. Social Narcissism

— Eric Rice (@ericrice) April 18, 2007

Wow. That's prescient.

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